This proposal requests funding for the predoctoral Chemical Biology Training Program at Stony Brook University (SBU). This interdisciplinary and interdepartmental Program offers chemical biology training opportunities for Ph.D. students selected from four participating units: the Biochemistry & Structural Biology, the Chemistry, the Molecular Genetics & Microbiology, and the Molecular & Cellular Pharmacology graduate programs. Participating faculty mentors (29) have research interests in infectious disease, cancer and toxicology, immunology, developmental biology, energy-harvesting, cell-signaling, organic synthesis, physical organic chemistry, enzymology, and materials chemistry. Trainees are educated in the principles and techniques of both chemistry and biology with a core interdisciplinary three-semester Chemical Biology course sequence. All trainees and mentors participate in the Institute of Chemical Biology and Drug Discovery annual symposium and poster session. This retreat is one avenue by which extensive interactions between students and faculty are fostered and the trainee group maintains a cohesive identity. The students meet for lunch with a Program Director or Mentor once per month during the academic year as a forum for feedback on careers, program assessment and two-way feedback. Trainees participate in their home graduate program research clubs and seminar series to broaden their knowledge and networking opportunities beyond the training program. In their fourth year, trainees work with Journalism faculty to convert their previously prepared research talks to presentations that non-scientists can understand and appreciate with the most compelling to be presented in a community outreach forum. Trainees invite outside seminar speakers. Instruction in the responsible conduct of research is carried out primarily through participation the course, Scientific Integrity. Recruitment of underrepresented groups is achieved through the SBU AGEP summer undergraduate research programs and extensive outreach. The number of mentors participating in the CBI Training Program is 29 and four funded positions are requested in the first year and eight funded positions are requested in subsequent years.